Navigation Links
Caffeine's effect on the brain's adenosine receptors visualized for the first time
Date:11/1/2012

Reston, Va. (November 1, 2012) Molecular imaging with positron emission tomography (PET) has enabled scientists for the first time to visualize binding sites of caffeine in the living human brain to explore possible positive and negative effects of caffeine consumption. According to research published in the November issue of The Journal of Nuclear Medicine, PET imaging with F-18-8-cyclopentyl-3-(3-fluoropropyl)-1-propylxanthine (F-18-CPFPX) shows that repeated intake of caffeinated beverages throughout a day results in up to 50 percent occupancy of the brain's A1 adenosine receptors.

"The effects of caffeine to the human body are generally attributed to the cerebral adenosine receptors. In the human brain the A1 adenosine receptor is the most abundant," said David Elmenhorst, MD, lead author of "Caffeine Occupancy of Human Cerebral A1 Adenosine Receptors: In Vivo Quantification with F-18-CPFPX and PET." "In vitro studies have shown that commonly consumed quantities of caffeine have led to a high A1 adenosine occupancy. Our study aimed to measure the A1 adenosine receptor occupancy with in vivo imaging."

Fifteen male volunteers participated in the study. They abstained from caffeine intake for 36 hours and then underwent a PET scan with F-18-CPFPX. Caffeine was then introduced in short intravenous infusions, increasing in amount. To estimate the occupancy of A1 adenosine receptors by caffeine, the distribution volume at the baseline period of the PET scan was compared with the distribution volume after caffeine administration. Researchers determined that the concentration of the caffeine that displaces 50 percent of the binding of F-18-CPFPX to the A1 adenosine receptor was 13 mg/L, or approximately four to five cups of coffee.

An important finding of the study is that in most regular coffee drinkers about half of the A1 adenosine receptors may be occupied by caffeine. It is likely that this blockage of a substantial amount of cerebral A1 adenosine receptors will result in adaptive changes and lead to chronic alterations of receptor express and availability.

"There is substantial evidence that caffeine is protective against neurodegenerative diseases like Parkinson's or Alzheimer's disease," noted Elmenhorst. "Several investigations show that moderate coffee consumption of 3 to 5 cups per day at mid-life is linked to a reduced risk of dementia in late life. The present study provides evidence that typical caffeine doses result in a high A1 adenosine receptor occupancy and supports the view that the A1 adenosine receptor deserves broader attention in the context of neurodegenerative disorders."

Caffeine is the most commonly consumed psychoactive substance worldwide and an active ingredient in innumerable food and beverages. Eighty percent of U.S. adults consume caffeine every day; the average for adults is 200 mg of caffeine per day (two 5-ounce cups of coffee or four sodas). It affects an individual's alertness, attention, cognitive performance, as well as reduces sleepiness.


'/>"/>

Contact: Susan Martonik
smartonik@snmmi.org
703-652-6773
Society of Nuclear Medicine
Source:Eurekalert

Related medicine news :

1. New MS drug proves effective where others have failed
2. New study shows effects of prehistoric nocturnal life on mammalian vision
3. Health inequalities could be reduced by more effective health care, says new study
4. Health inequalities could be reduced by more effective healthcare, says new study
5. Genes May Determine Aspirins Effect on Advanced Colon Cancer
6. As painkiller overdoses mount, researchers outline effective approaches to curb epidemic
7. Is magnetic therapy effective for tinnitus?
8. Considerably more patients may benefit from effective antidiabetic drug
9. Surgery more profound effect than anesthesia on brain pathology, cognition in Alzheimers mice
10. NIH-funded analysis estimates effective PrEP dosing
11. Effects of stopping alcohol consumption on subsequent risk of esophageal cancer
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:10/13/2017)... ... October 13, 2017 , ... Coveros, ... Development, has been awarded a contract by the Center for Medicare and Medicaid ... to accelerate the enterprise use of Agile methodologies in a consistent and high ...
(Date:10/13/2017)... ... October 13, 2017 , ... “America On The Brink”: the ... “America On The Brink” is the creation of published author, William Nowers. Captain ... As a WWII veteran, he spent thirty years in the Navy. Following his ...
(Date:10/12/2017)... ... October 12, 2017 , ... CitiDent and San Francisco ... using cutting-edge Oventus O2Vent technology. As many as 18 million Americans are estimated ... in breathing. Oral appliances can offer significant relief to about 75 percent of ...
(Date:10/12/2017)... ... October 12, 2017 , ... The ... demand of today’s consumer and regulatory authorities worldwide. From Children’s to Adults 50+, ... to meet the highest standard. , These products are also: Gluten Free, ...
(Date:10/12/2017)... MD (PRWEB) , ... October 12, 2017 , ... The ... of Excellence to Carol Friedman, PhD, FACMI, during the Opening Session of AMIA’s Annual ... – 8. , In honor of Morris F. Collen, a pioneer in the field ...
Breaking Medicine News(10 mins):
(Date:10/2/2017)... 2017 Halo Labs announces the European launch of their ... HORIZON at MIBio 2017 in Cambridge, U.K ... matter in biopharmaceutical samples with unprecedented speed and sensitivity while using ... Backgrounded Membrane Imaging. ... subvisible particle analysis system ...
(Date:9/27/2017)... MIAMI , Sept. 27, 2017  Commended for their ... recent notable awards. Ranked as number one in the South ... ninth time in Inc. 5000 yearly list, the national specialty ... CEO, Armando Bardisa will soon be honored by ... Set to receive his award ...
(Date:9/23/2017)... Sept. 22, 2017 Janssen Biotech, Inc. (Janssen) ... letter from the U.S. Food and Drug Administration (FDA) ... sirukumab for the treatment of moderately to severely active ... clinical data are needed to further evaluate the safety ... active RA. ...
Breaking Medicine Technology: